Particular embodiments generally relate to video coding.
Several applications, such as streaming video, video conferencing, etc., transfer moving pictures. The information that is transferred is typically digital video that is represented by information for pixels in a picture. Data transmission lines are often unable to carry uncompressed data for the moving pictures. Thus, data compression is used to compress the data. Typical standards include moving pictures expert group (MPEG)-x and H. 26x standards. Specific examples of standards include MPEG-4, H.264, etc.
In H.264, video data is compressed using a transform step, such as a discrete cosine transform (DCT), and a quantization (Q) step. Also, an inverse transform and inverse quantization may also be performed for motion estimation. These computations are computationally intensive. In some cases, all of the DCT coefficients may be quantized to zero. In this case, the computations may be skipped. In MPEG-4, Sum of Absolute Differences (SAD) values can be used to determine if the computations can be skipped. The SAD value is calculated in the motion estimation calculation of the video coder. However, in H.264, the SAD may not always be used in the motion estimation. When this is the case, the determination of whether the computations can be skipped cannot be performed using the SAD value.